Gun.



No. 678,557. Patented July l6, 19m,

' E. GATHMANN.

. '6 U N- N o M o d e I.) (Application filed Nov. 8, 1900.)

77 .1,- i M 7 6 a UNiTnen STATES PAT T @rricn.

EMIL GATl-IMANN, OF "WASHINGTON, DISTRICT OF COLUMBIA.

GUN.

SEEGIFICATION forming part of Letters Patent No. 678,557, dated. July 16, 1901.

Original application filed March 16 1899, Serial No. 709.279. ilo. aaasv.

To. all whom it 1mg concern:

Be it known thatl, ELHLTGATHMANN, of Washington,in the District of Oolum bia, have invented certain new and useful Improve ments in Guns, of which the following isa specification. s

This invention relates to improvements in rifled breech-loading guns, and refers more specifically to that class of ordnance adapted for throwing large masses of high explosives in shells or aerial torpedoes, the present application being filed as a division of application Serial No. 709,279, filed March 16, 1899.

' The invention has for its object to provide a novel construction in the bore of a gun of the character referred to, whereby the shell charge will be subjected to a thorough setback by the expelling charge before the torp'edo or shell is influenced or acted upon by the rifling of the gun, thereby insuring corotation of the shell-body and itscontents or charge.

The invention also has in view the production of a construction which will insure a gradual and easy entrance of the rifling lands or ribs into the rotation-bands of the projectile, thereby insuring a uniform and low chamher-pressure with relatively high initial densities of loading. The construction further provides for an intimate and complete contact of the rotation-bands of the projectile with the walls or bore of the gun, thereby preventlngerosion and wash,which are mainly due to the passage of the propelling powdergases between the walls or bore and the rotation-bands.

To these ends my invention consists in certain novel features of construction, which I will now describe and will then more particularly point out and specify in the appended claims.

In the accompanying drawings, Figure 1 is an axial sectional view of a gun embodying my invention, the rear end portion thereof being broken ed to reduce the size of the figare. Fig. 2 is a fragmentary sectional view of a-portion of the gun, on a larger scale, and showing a portion of a projectile in elevation. arranged therein. Fig. 3 is a view similar to Fig. 2, on a still larger scale. Fig. 4 is a simi- Dividedaml this application filed November 3, 1900. Serial (life model.)

.lar fragmentary view illustrating the relation of the shell to the bore when the same has;

advanced some distance along the bore of the gun. Fig. 5 is another similar view showing the projectile still further advanced along the bore and in that portion of the latter when it is just entering the fully-rifled part thereof. Fig. 6 is a transverse fragmentary sectional view of the riding of the gun, taken on line 6 6 of Fig. 1. Fig. 7 is a similar view taken on line 7 7 of Fig. 1.

In breech-loading ordnance as now generally constructed the projectile is provided with a rotation-band, made of copper or the like, which is somewhat larger in diameter than the bore of the gun, measured from the bottom of the rifliug-grooves, the bore of-the gun being ordinarily provided with rifling terminating quite abruptly at or near the for ward end of the powder-chamber at what is termed the compression or forcing slope. A relatively large amount of force is required to start or enter the band of a projectile into the riding when the latter termimates in this abrupt or short slope, as has hitherto been the usual case. 1

In practice it has been found, particularly with guns of large diameter of bore, that the abrupt termination of the riding and consequent heavy forcing required to start or enter the projectile within the rifling causes irregular and high chamberpressizre, great erosion, and wear upon the rear portion of the bore of the gun, and when large masses of'high explosives are carried in projectiles undue measures of shock and friction are transmitted to the explosive by reason of this violent motion imparted to the projectile during the moment its hand is being forced into the riding. It is to obviate this and other objections that I provide the construction shown in the accompanying drawings, in which 10 indicates as a whole the body of a gun having at its rear end the usual powder or charge chamber 11 and immediately in advance of this a short position-slope 12.

ing intermediate this position-slope 12 and the fully-rifled portion of the bore 13 is a conical shell-chamber 14, preferably and as shown herein of unifornr decreasing taper toward the riding, as shown clearly in the several figures of the drawings, and merges gradually into the rifled portion of, the here at its forward end, being, however, of greater diameter than the body or shell at its forward and smaller end.

A projectile-such, for example, as that in-- dicated at 15-provided with any suitable or desired compression rotation-band, as indicated at 16, constructed of copper or analogous material, is inserted in the chamber and pushed forward until its hand 16 engages the position-slope 12 and its bourrelet 17 has entered the cylindrical fully-rifled portion 13 ot' the bore of the gun.

. 1B deslgnatts'the lands of the rifled portion of the gun, and 19 the grooves or rifles proper, these being shown in their normal width and depth in Fig.7.

385 Fig. 0, designates the lands and ridegreoves as they appear in cross-section, taken on line U U of Fig. 1 or through'the forward part of the she l-chamber, where the latter merges into the main eylindric bore of the.

glut, said figure being intended to bring out clearly the reduced heights of said lands in this art of the shell chamber, the lands iinel yrunningoutentirelyat that point inthe shell-chamber which is of the same diameter as the diameter of the'inain bore, including the depth of the rifle-grooves 19. A gun having a bore constructed as thus described when loaded'with and firing a'projectile provided with an y suitable compression rotation, band-such, for example, as that described hereiuoperate's substantially in the followingmanner: Upon the'explosion of the propolling charge the projectile moves forward and the rotation-band of the same enters within the conical shell-chamber 14, and while moving forward through this part of the bore the taper or gradual decrease in diameter of the shell-chamber exercises a compressing action upon the rotation-band 16, which acts to gradually swage the same into position upon the lands of the riding of the bore of the gun substantially in the manner indicated in the series of progressive positions indicated by Figs. 3, 4, and 5.

In Fig. 4 of the drawings the shell is shown in thecondition in which it exists when the compression or rotation band has passed her, forming an eifectual gas-check to arrest the flow of propelling-gases past the band. As the projectile travels forwardly the fit of the band within the chamber becomes tighter and tighter and the friction consequently greater, but the projectile meanwhile gains energy from its own momentum as well as from the increasing pressure of the propelling-gases, so that when the rotation-band finally enters the fully-rifled section of the bore, as shown in Fig. 5, it does not occasion any sudden jar or strain to either gun or projectile, as is the case with guns as heretofore usually constructed havingthe abrupt entrance from the shell-chamber to the riding.

As before stated, the gradually tapering or decreasing diameter of the shell-chamber exercises a compressing-or swaging action on the rotation-band of the projectile and avoids the cutting or planing eifect produced by the usual form of bore wherein the projectile enters abruptly to the riding.

A special form of rotation-band such as described in my United States application, Serial No. 709,279, may be advantageously used in guns constructed with a shell-chamber of the type herein described, but any other form of suitable compression-banded projectile may obviously be used if the band he made of suitable diameter.

By the compressing and swaging action of the tapered shell-chamber upon .the rotation-band of the projectile a very perfect gascheck is insured immediately upon the entrance of the band to this chamber and the destructive wash and erosive actions due to the highly heated powder-gases passing the projectile while within the bore of the gun are thereby obviated.

This construction of gun is particularly ap- It willbe seen that as the first or initial movement I of the projectile when being fired from the gun is entirely and only a direct forward move ment, a thorough set-back is imparted to the shell charge before the rifled portion of the gun is entered, thus insuring a corotation of t the charge of the shell with the latter when rotary motion is imparted by the riding. The tapered shell-chamber also reduces the power necessary to overcome the combined inertia of the projectile and frictional resistance of the bore thereon for the reason that the foreing required to enter the rotation-bands within the riding is much less than with other systems or constructions. More uniform and relatively lower chamber-pressures are there for agiven muzzle energy.

It will be obvious that modifications may be made in the details of riding, in the length of and taper of the shell-chamber, and otherwise without departing from the spirit of the v jectile-chamber between the charge-chamber and main bore, having uniformly-tapered sides which merge into the main bore at the forward end of said chamber.

.3.. In a gun, the combination of a chargechamber, amain bore of substantially less diameter than the chargechamber and provided with rifling, and a projectile-chamber between the charge-chamber and main bore having a gradually diminishing diameter from its rear end forwardly and merging into the main bore at its forward end.

the combination of a charge- 4. In a gun, the combination of a chargechamber, a main bore of substantially less diameter than the charge-chamber, and provided with riding, a projectile-chamber between the charge-chamber and the main bore, of gradually-diminishing diameter from its rear end forwardly and merging into the main here at its forward end, and a relatively abrupt position-slope between the charge-chamber and projectile-chamber, substantially as described. f

5. In a gun, the combination of a chargechamber, a main bore of substantially less'diameter than t-he charge-chamber and a projectile-chamber between the charge-chamber and main bore, ameter from its rear end forwardly and merging into the main bore at its forward end, said main bore being provided with riding continued back into the forward portionof said projectile-chamber until it vanishes in the tapered sides of the latter, substantially as described.

EMIL GATHMANN.

Witnesses:

- E. A. PAUL,

AUG. I-I. BECK.

of uniformly-decreasing di- 

